Legal Question in Family Law in California

There's no prohibition with both parties continuing to reside in the same residence even after the divorce is complete. You could benefit from meeting with an experienced family law attorney to explore your legal options and be certain that the preparation of any agreements are done in a fashion that will be enforceable.

Sure. Perfectly fine and not really all that uncommon if they are getting along well enough for that to work.

I agree as long as there is not a dispute between the parties as to the date they intend to use for their date of separation.